Gauge



0d 24, 1933 F. s. GRuvER ET AL 1,932,159

GAUGE Filed Oct. l, 1950 fff//' 'l' 7 4./ Ja/ J5 /4 gmanoz Patented Oct. 24, 1933 I UNITED STATES v, g g1,932,159

:PATENT OFFICE V1,932,159 t' GAUGEv Frank S. Gruver and Emerson Aachenb'ach, Sellersville, Pa., assignors to United States Gauge Company, New York, N. Y.,fa corporation of Pennsylvania Application Qctober 1, 1930. Serial No. 485,751,v

16 Claims.

like to register pressures. The term pressures, is, of course, here used to denote negative or absolute pressures-as well as those above atmospheric.

i1o In pressure gauges ot the type above described the parts of the operating mechanism .often undergo such changes, through wear and distortion and the like, as to render inaccurate readings. The most common defect in gauges now in bration, so that the pointer does not align yitself with the initial or zero mark on the dial when it should, and hence gives inaccurate readings for all positions of the pointer. It has been proposed to remedy this defect by providing manual 'adjustments for the pointer and even for the dial. These adjustments, however, are inconveniently made by shifting an element to some selected fixed position and vmust be made so often as to cause annoyance, and often are overlooked either through ignorance, indifference orlcarelessness.

Accordingly it is a primary object of the present invention to provide a gauge the indicating mechanism of which may be brought into proper calibration merely by shifting a conveniently disposed movable means that is associated with lthe indicating mechanism. In this connection itv is a major object of our invention to design a gauge in such manner that a correctionr of the inaccuracies, it any, is accomplished automatically each` time that the gauge is operated to record a r ding.

Several more specific objects, subordinate to the above ultimate objects, are, in a gauge having a dial and a pointer, to cause a continued and definite calibrated alignment of the pointer and `the initial point of the dial; to provide a shiftable dial which is operated automatically, as the pointer returns toward zero position, to assume of the pointer; to provide a shiftable dial having a ilxed point thereon, as a stop pin, to meet the pointer as the latter returns to its initial position, and having a brake or lock to hold the dial to serve in combination with ythe features just outlined.

Further objects appear fromv the followingl use is that the pointer and dial get out of cali-`vl yend anchored 'in manner to be subjected to the pressure iiuid 'ada set position accurately corresponding with that.

after its stop pin has engaged the pointer and' detailed description and the accompanying draw- 111g, wherein:

Figure 1 is' a face view,with the cover removed and the mechanism in zero position, o! one type of gauge embodying a preferred form o of our invention.

'FigureZ is a view, in partial section, taken on the jplane oi' line 2-2 ln lFigure 1, with vthe mechanism shown in' elevation and in extended position for the measurement of Vhigh pressure. o5

Figure 3 is a' face view of the mechanism of Figure 1 removed from the casing and with the dial and its brake detached for clarity oiillus tration.V

The particular device illustrated in the draw- 7o ing is especially designed for use where readings are to be taken at intervals land the pointer to be reset to zero position after each reading, as when measuring the pressure in pneumatic tires. It will be understood-that the principles of this invention are readily applicable to many other types of gauges, with and without modification. With 'continued -reference to the drawing,

wh'erein like numerals are employed to designate like parts, the numeral 4 indicates a cup-shaped 80 casing having a hole 5 in. its annular wall. A

mounting block` 6, disposed within the casing and secured iirmly against the back wall of the latter'by a screw '1, has an integral threaded extension 8 projecting through the hole 5 to re- 85 ceive a conduit 9 adapted tofcommunicate with a pressure source. A'Bourdon tube 11 has one the block 6 in conventional mitted through the conduit'9 and the extension 90 8. The free or closed end oi the tube has a bent actuator 12 soldered or otherwise secured thereto. Expansion of the tube in response to pressure fluctuations is utilized to indicate` pressures by way of the followingl mechanism:

' A pin 13, having a head 14, is driven -or otherwlsetlrmly set into the mounting block 6. Upon this pin there is oscillatablypivoted a substantially U-shaped device 15 comprisinga pointer 16 piv-` oted adjacent the pin head, an actuated pivoted adjacent'the block 6, and a bar 18 integrally interconnecting the pointer and the actuated arm 1'7.` The latter has `an offset actuated finger 19.bent over toward the pointer, the end of this finger being pivotally connected, as at 21, 165` to one end of an actuated-link 22. The opposite end of link 22 is enlarged and has a longitudinal closed slot 23 therein for slidably receivingva pin 24 that projects into the tube-carried actuator 12'.

It will thus be seen that, as the Bourdon tube arm 17 1002 expands, it lifts the slotted end of the link and causes the latter to swing the device 15 and its pointer 16 in a clockwise direction.

The purpose of the slot 23 is to permit the tube to return to contracted position without moving the pointer from its position of indicated pressures. A dial 20, marked as shown for cooperation with the pointer, is mounted upon the pin 13. The pointer is steadied, and maintained in indicating position after therelease of operating pressure, by means comprising a drum 25 rigidly soldered or otherwise secured to the rear face of the arm 17 and freely surrounding the pin 13, and further comprising a wire spring 26 having one end setI into a lug 27 on the block 6 'and its other end frictionally bearing against the periphery of the drum. Means is provided for conveniently resetting the pointer to its initial or zero position after each pressure indication, as follows:

A flat spring 28 (see Fig. 1) has one end riveted, as at 29, upon the inner wall of the casing. 4 in such manner that its other end terminates adja cent the arm 17 of the device 15. The last mentioned end resiliently bears against an enlargement 31 of a plunger 32 that is reciprocable through the wall of the casing. The spring carries a button 33 designed, when one presses inwardly upon the plunger with his thumb to overcome the resistance of the spring, to bear against a camming surface 34 formed on the arm 17. Continued thumb pressure causes the cam to slide past the button until the pointer is oscillated to its zero position. l

The dial 20 is not fixed upon the pin 13, but is secured to a brake drum 35 which, together with an integral sleeve 36, is freely pivoted upon the pin 13. A light wire spring 37 has one end soldered to the drum 35, as at 38, and has its other end reacting against the block 6 in such manner as to tend to oscillate the drum `and dial a clockwise direction. This spring action must not be suiciently strong, when a stop element 39 on the dial engages the pointer, to overcome 'the braking resistance of the wire spring 26. The reason for this will become apparent later. A braking or locking device for the dial is provided, as follows:

The brake drum 35, to which the dial is secured. has a peripheral groove'41 on its surface, into a portion of which groove there fits the inner edgeof a curved'braking arm 42. One end of the braking arm is pivoted on the block 6 by a screw 43 and to this end of the arm there is soldered or otherwise secured at 44 a curved wire spring 45 which reacts against the casing 4 in such. manner as to swing the arm in a clockwise direction 'against the brake drum 35. This serves to lock the dial in zero position, but means is provided for releasing it during the pointer resetting operation.

This means comprises a. brake-release finger 46 that is integrally formed with the brake arm and projects laterally therefrom into proximity to the camming surface 34 and the push button 33. When the latter is thrust inwardly during the return movement of the pointer it first engages the cam 34 and then, substantially at the moment that the pointer arrives at its zero position, 'the button engages the release nger to disengage the lbrake arm from the drum groove 41,. Further inward movement of the button causes the pointer the latter having been contracted slightly from its natural or free zeroiposition. Hence, when the push button is released the first thing that occurs is a slight expansion of the tube to its natural or free position which, of course, is the true and accurate Zero position.. DuringV such tube expansion the pointer is drawn, by way of the actuator 12, link 22, finger 19 and arm 17 into a corresponding true and accurate zero position. Due to the action of the steadying wire 26 that engages the drum 25, the pointer will not pass the point to which it is positively drawn by the expanding Bourdon tube.

The next event that takes placev (substantially simultaneous with the pointer movement just described) is the clockwse rotation of the dial in response to the action of its light spring 37. The dial rotates until its stop pin 39 engages the pointer and it is then brought to a stop because the spring 37 cannot overcome the braking re- 95 sistance of the wire 26. Substantially at the same moment the brake arm 42 is permitted t'o come into engagement' with the dial drum 35 'and lock the dial in position. Both the pointer'and d`al are now in alignment in their true zero posi- 00 tion (corresponding to the exact natural'zero position of the Bourdon tube) and the gauge is ready to be pressed upon a', tire valve. ori-the like to take a pressure reading. l

Although a number of individual steps or oper:- 105 ations have beenl described above it will be understood that the resetting is practically instantaf'- neous, since all `one has to do is to depress land. then release the plunger 3'2. The indicating- A mechanism always is maintained automatically 10 in correct position and relationship;v s thatno additional calibrating means or adjustments are necessary. The zero position;` frequently "rei ferred to is, of course, any initial' or 'predetermined position. A diaphragm or lthelike 'may be 3515 substituted for the Bourdon tube, and the invenltion may be embodied in gauges other than posi-v tive pressure gauges. If desired, the-thumb Imagnipulated device'may beabolished and the cony nection between the Bourdonl tube and lthe i mechanism be so modified that contraction of the tube will automatically operate during' theresettng f the pointer to actuate the release'ng'er -46 in a manner similar to that above described.

The invention may be embodied lin other lspe 25 cinc forms without departing Afrom the spirit `=or essential characterstics thereof. The present embodiment is therefore'to beconsideredl in'v all respects as illustrative and not restrictive, the scope of the invention being indicated by the ap'- '130 pended claims rather than by the foregoing description, and all changes which come within"t'he vmeaning and range of equivalency of the claims are therefore intended to be embraced,` therein. u

What We claim and desireto secure byUnitetl States Letters Patent is:

1. In a gauge having an indicating-mechanism designed to be returnedto any initial position after each reading, means for actuating said mecha)- nism to indicate a measurement value, 'means 140 for resetting said mechanism toits initial 'position, and means for automatically 'making' a'corirect adjustment of the indicating' mechanism when the latter is returned to its linitial position by said resetting means.V y A145 2. In a gauge, an indicatingmechani'sm, means for actuating said indicating mechanism, means for automatically maintaining the" indicating mechanism in correct calibration or adjustment during the normal operation of the gauge, and a manually operable device conveniently manipulated from without the gauge, said automatic means being operable in response to manipulation of said device.

3. In a gauge construction, an indicating mechanism comprising a dial and a pointer or the like cooperating therewith, means for actuating said indicating mechanism, and means automatically maintaining the indicating mechanism in correct adjustment during operation of the gauge, said automatic means comprising a device for aligning said pointer with its correct position on said dial when the indicating mechanism is actuated in one of its directions of movement.

4. In a gauge having an indicating mechanism designed to be returned to an initial position after cach reading, means for actuating 'said mechanism to indicate a measurement valuefmeans for automatically making a correct adjustment of the indicating mechanism when the latter is returned to its initial position, said indicatingmechanism comprising a dial and a pointer, and a manually operable device for returning said mechanism to initial position and rendering said automatic means operative to align the pointer with its correct initial position on the dial.

5. A gauge comprising a pressure-responsive element, an indicating mechanism actuated by said element to render visible pressure readings, and means for automatically maintaining said indicating mechanism in accurately adjusted relationship to said pressure-responsive means to indicate true positions of the latter during normal operation of the gauge.

6. In a gauge having an indicating mechanism designed to be returned to an initial position after it has registered a pressure indication, a pressureresponsive element for actuating said mechanism to indicate a pressure value, and means for making any necessary corrective adjustment of the indicating mechanism, said means being automatically operable in response to return movement of said mechanism to its initial position.

7. In a gauge construction, a shiftable dial, an indicator cooperating with said dial to render visible readings, means for operating said indicator, means for normally holding said dial in xed position, means for releasing said holding means, and means, operable when said holding means is released, for shfting said dial into correct'position relative to said indicator.

8. In the combination defined in claim '1,'said holding means comprising a yielding friction brake.

9. In the combination set forth in claim '7, said holding means comprising a member mounted for unitary movement with said dial and an element yieldingly pressed into engagement with said member.

10. In the combination speciiied in claim '7, said releasing means comprising a manually operable device for resetting said indicator and substantially simultaneously releasing said holding means.

11. In the combination of claim 7, means for frictionally resisting movement of said indicator, and said shifting means comprising a resilient device for urging said dial in the direction of the indicating movement of the indicator.

12. In the combination dened in claim '7, said indicator comprising a pointer, said dial having a stop device for engaging the pointer upon return movement of the latter to its initial position, and said dial shifting means comprising a resilient device for actuating the dial to urge said stop device toward said pointer when said holding means lis released.

to bring an initial position on said dial into exact f alignment with a portion of the pointer.

14. In the construction deiined in claim 13, said last-mentioned means comprising means for urging the dial in the direction of pointer indication, means constantly resisting pointer oscillation, means for normally locking said dial against oscillation by said urging means, and means for tcmporarily releasing said locking means when the pointer is reset to its initial position.

15. In a. pressure gauge in combination, a dial and an indicator, mechanism for actuating said indicator in one direction to cause it to render pressure indications on the dial, pressure-responsive means connected with said actuating means to operate the latter, means for retaining said indicator in its indicating position after the pressure has decreased in said pressure-responsive means, means for resetting said indicator to its initial position after the pressure reading has been taken, and means automatically operable, upon movement of said resetting means, to adjust said pointer and dial into proper relationship to indicate an initial pressure condition at the exact moment that said presure-responsive means is in its initial position.

16. In the combination defined in claim 15, said pressure-responsive means comprising a Bourdon tube having a connection at its free end with said actuating mechanism, said connection being designed to permit said free end to return to initial position without a corresponding movement of the indicator, and said resetting means comprising a cam carried by said indicator and a manually operable device designed to be thrust into engagement with said cam and said automatically operable means.

FRANK S. GRUVER. EMERSON ASCHENBACH. 

